Dental casting machine



AQAES? POLLEN Jun@ 3 B924, C. O.

DENTAL CASTING MACHINE Filed July 24, 1922 Patented lune 3, 19243.

D rArEs CLARENCE O. POLLEN, F TACOMAP WASHINGTON.

DENTAL CASTING MACHINE.

application med July 24,

To all whom t may concern Be it known that I, CLARENCE O. POLLEN, acitizen of the UnitedStates, and a resident of Tacoma, county of-Pierce,and State of Washin and useful mprovements in Dental Casting Machines,of which the following is a specification.

This invention relates to improvements in machines for dental casting,and more particularly to machines of that character which utilize theprinciple of centrifugal force for distributing the metal properlywithin the mould.

It is known that machines for the above purpose, which utilize theprinciple of Centrifugal force, are already in use, such machinescomprising a mould and a Crucible th-at are mounted on a supporting arm'which is revolved in such manner that the metal will be caused to flowfrom thecrucible into the mould. In such machines, there are severaldisadvantages; the principal one being that the metal is force by thecentrifugal force to the outer end of the mould and consequently buildsup faster there than it does toward the inner part of the mould, therebycausing the walls of the mould to be distorted to such an extent'that itis often necessary to make. a new impression.

lt is the principal object of this invention to improve upon themachines, as above stated, and to thereby overcome the disadvantages asnoted, by the provision of additional means whereby the Castin mouldwill be rotated at a high rate wlthin its supports to cause the metaldelivered thereinto to be distributed equally. to all parts thereofwhile, at the same time, the support, the crucible and mould will berevolved only at such rate of speed that is' suicient to thereby Causethe casting metal l to be delivered-into the mould.

ln accomplishing these and other objects of the invention, l haveprovided the improved details of construction, the preferred forms ofwhich are illustrated in the accompanying drawings, wherein- Figure 1 isa side view, partly in section, of a dental casting machine constructedin accordance with the present invention.

Figure 2 is a plan view of the same. Referring more in detail to thedrawingsj 1 designates a base plate and 2 a gear on, have inventedcertain new 1922. Serial No. 577,064.

housing mounted thereon; the latter having .a vertical shaft 3 revolublysupported therein and equipped with a gear 4 that operates in mesh witha larger driving gear wheel 5 fixed on a supporting shaft 6 to which aprank 7 is attached,` and whereby vthe gear 5\may vhe rotated to effectrotation of the shaft 3. The upper end ofthe shaft 3 extends through asleeve 8 that is fixed within the housing and which, at its upper end,has a beveled gear wheel 9 non-rotatably fixed thereto. I

Secured to the upper end of the shaft 3, isa horizontal arm 1() having aCounterbalancing weight 11 adjustably fixed onone end thereof and havinga casting mould mounted at the opposite end. The mould comprises aCylindrical 'Casing 12 clamped at its opposite ends, between supportingdiscs 13 and 14; the former havin@ a hollow hub portion 15 rotatablymounted within a supporting bracket 16 that is adjustable along the armand which may be locked at adjusted positions by means of a set screw 17threaded through the bracket and against the arm. The disc 14 has asupporting shaft 20 mounted revolubly within a standard 22 at the endofthe arm 10, and, provided at its outer end with a gear wheel 23 thatoperates in mesh with a similar gear 24 fixed to the outer end of ashaft 25 that extends parallel with and beneath the arm 10, and which,at its inner end, has a beveled gear 27 operating in mesh with thenon-rotatable gear Wheel 9. The shaft 25 is revolubly supported inbearings 28 and 29 formed as a part of the arm 10.

The hub portion 15, which supports-the disk 13, is hollow and, extendingtherethrough, is a spout 32 of a' Crucible 33 ,Y wherein metal for thecasting purpose may be melted; the cruCible being supported within aseat 34 formed as a part of the bracket 16.

Assuming that the machine is so Constructed, to use the same, first, theinvestment is properly made within the mould and this will have a sprueopening leading to the hub 15, of the disc 13, so that the metal mayflow thereinto from the spout of the Crucible. The metal is then meltedin the Crucible by means of a blow torch and when it is in the properform the parts are set in motion by turning the crank 7. This causes theentire mould and Crucible to be revolved about the shaft 3, while at thesame time the mould 12 is rotated on its supporting axis by means of thegear connection provided; itbeing apparent that since the gear`wheel 9is ixed, the gear 27 will be caused to rotate as it is carried about theshaft 3 .and this, in turn, will effect rotation of the gears 24 and 23,and the casting mould connected with the latter. When the mould isrevolved at sufiicient Speed, the molten metal will be carried, bycentrifugal force, from the crucible into the sp1-ue opening of theinvestment and will fill the mould. At the same time the mould isrevolved it is rotated, and this eii'ccts an equal distribution of themetal over all parts of the investment. The gearing ratio is such thatthe rate of rotation of the Crucible and mould would be only suiiicientto cause a flow of metal from the crucible into the mould while the rateof rotation of the mould would be much faster so as to cause thecentrifugal `force of the metal away from the center of the mould to,overcome its centrifugal force with respect to the supporting shaft 3.

It is readily apparent that by the use of n machine of this character,any building up of the metal at the outer portion of the mould will beovercome and that, in this way, the distortion of the Walls of the mouldis eliminated.

It. is possible t0 obtain this result by mechanism not like that shownand, for

ramene y ,g this reason, do not wish to be limited only l. A castingmachine of the class del scribed, comprising a rotatable su ortng shaft,an arm fixed to extend laterally. from the shaft, a casting mouldrotatably fixed on said arm having an end opening, a crucible adjustableon the arm at the inner side of the mould, having a delivery spoutextended into registration with said mould opening, means for rotatinthe supporting shaft to revolve themou d and Crucible, and means forrotating the ,mould while being revolved by said arm.

2. A casting machine comprisin a rotatable supportin shaft, an arm xextend laterally From the shaft, a casting mould rotatably fixed on saidarm having an end opening, a Crucible having a delivery spout intoregistration with said mould opening, a gear fixed concentric to thesupporting shaft, a gear on the supporting axis of the mould and .adriving shaft rotatably supported from the arm having gears thereonmeshing with the first gear and the mould gear, and means for rotatingthe supporting shaft.

Signed at Seattle, Washington, this 18th day of July, 1922.

CLARENCE 0. POLLEN.

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